Etching machine



Feb. 13, 1934. w UE T 1,947,391

ETCHING' MACHINE Filed Dec. 2, 1932 3 Sheets-Sheet l IN V EN TOR.

[VZZZQ/fi 6256415 TORNEY.

3 Sheets-Sheet 2 W. GUENST E'ICHING MACHINE Filed Dec. 2, 1932 Feb. 13, 1934.

w a ie- Ii Feb. 13, 1934. w. GUENST ETCHING MACHINE Filed Dec. 2, 1932 3 Sheets-Sheet 3 INVENTOR.

Patented Feb. 13, 1934 UNITED STATES PATENT OFFICE i 21 Claims.

This invention relates to improvements in etch-V 10 within the receptacle, will operate to increase the capacity of the spraying means to break up the liquor and mix it with air and increase the quantity and improve the quality of the spray delivered to the plates and thereby speed up the etch 715 ing process.

Another object is to provide a means whereby the operation of the paddles of the spreader with relaticn to baiiie andthe liquor level may be adjusted and regulated for the production of the 2 desired spray.

Another object is to provide a novel and advan-= ta e'ees means for preventing etching liquor from leaving the receptacle through the openings in the walls thereof through which the shaft of the spreader extends, during the spraying operation.

Another object is to provide a means for supporting plates of dilferent sizes within the receptacle, and in such relation to the walls thereof and to the spraying means that any sprayed liquor delivered to the plates above the upper edges thereof may pass the plates and flow down back of the same, instead of flowing down over the surfaces to be etched, for the prevention of undercutting.

A further object is to provide a novel and adjustable over flow device for regulating the height of the liquid level within the receptacle and its relation to the paddles of the spreader.

The invention consists of the elements and the combinations of them hereinafter described and (claimed.

In the accompanying drawings illustrating the invention,

Figure 1 is a front view of an etching machine, showing one form of embodiment of the illustration.

Figure 2 is a side View thereof. 7

Figure 3 is a vertical section of the machine, on line 33 of Fig. 2.

Figure .4 is a vertical section of the machine, on line 4-4 of Fig. 1.

Figure 5 is a horizontal section of the machine, on line 5-5 of Fig. 4, showing a part of the baffle broken away.

Figure 6 is a sectional detail, enlarged, showing a part of the acid spreader and a part of a wall of the receptacle.

Figure 7 is a section of the spreader, on line 7-7 of Fig. 6. v V A Figure 8 is a section through the parts shown in Fig. 6, on line 8-8 of Fig. 6-.

Referring to the drawings, 9 designates a receptacle comprising a bottom wall 10, side walls 11 and front and rear Walls 12 and 13, respectively. The receptacle 9 is adapted to contain the etching, liquor for the etching process, and. it may be constructed of any suitable material which is resistant to the action of such liquor, such as stoneware.

The front wall 12 of the receptacle is provided with a baflie wall 14 which extends therefrom toward the rear wall 13 and which extends between the side walls 11 the full width of the receptacle, or substantially so.

Extending transversely through the receptacleflo below the baflle wall 14 and in parallel relation thereto is a rotatable shaft 15 provided with a driving pulley 2 and carrying a liquid spreader which is formed in a plurality of sections 16, each section being formed of suitable material which;. is resistant to the action of the etching liquor. Each spreader section 16 comprises a central hub 17 through which the shaft 15 extends, and paddles 18 and 19 extending from the hub 17. The paddles of each section extend the full width thereof and they are alined for rotation in a common path. The paddles 18 alternate with the paddles 19 and they are made longer and extend a greater distance from the shaft 15 than the paddles 19, for a purpose presently'explainedi The free end portions of the paddles 18 and19 extend from the inner or body portions thereof forwardly or in the direction of rotation of the liquid spreader, as indicated by the arrows in Figs. 4 and 7. The long paddles 18 of each sec-. tion 16 are arranged opposite to the short paddles 19 of the next adjacent section or sections. The ends of the spaces between the paddles-of each spreader section 16 are closed by discs 20 which are carried by the shaft 15 between the; sections and outwardly of the end sections; and the sections and discs are clamped together by and between sleeves 21 on the shaft 15 and nuts 22 screwed on to the shaft and engaging the outer ends of the sleeves. 3-

The bottom of the baffle wall 14 is made hollow or concave, as shown ini ig. 4, and the liquid spreader is positioned so that, during the rotation thereof,- the free ends of the long paddles 18 of its sections 16 will pass the free edgeof the baflle Wall 14 in close proximity thereto but spaced therefrom, and so that the free ends of the long paddles 18 will pass below the level of the etching liquor 23 and the free ends of the short paddles will pass above or clear such level. The effect of this arrangement of the parts is that the long paddles 18 will dip into and pick up the etching liquor and the short paddles will blow air into the concavity of the wall 14 and both the long and the short paddles will throw the liquor into the cavity formed by the hollow bottom of the baille wall 14 and discharge the air and liquor mixture between the paddles and the'free" end of the baffle wall 14 and project it in aflnely divided, flaring spray toward the rear wall 13 of the receptacle, as indicated by-the dash lines in Fig. 4.

The provision of the alternating long and short paddles 13 and 19 permits the etching-liquor to flow into the path of the outer end portion of each rapidly rotatinglong-paddle 18, following its dipping operation, before the succeeding long paddle reaches the liquor and, at the same time permits the employment of a suficient number of-paddles for the production of an efiicient spray;

Any liquor that-falls down back of the long paddles 18, after being thrown thereby up against thebaflie wall 14, drops upon-the succeeding short paddles 19 and iscaught thereby and thrown up against the baiiie 14andout from under the same and thereby broken up and added to the spray. In machines where the paddles of the spreader havebeen made of'uniform length and a like alas number of paddles have been employed, it has been found'that the free end portions of the pad- '--d1es tend to produce a depression in the body of the etc-hingliquor corresponding with thepath of the bladesbelow the level of the liquor, due to the rapid rotation of the spreading device, be-

cause there is'nQt-suflicient time for the liquor to 'flowinto such depression between the dipping operations of the successive paddles. My improved construction and arrangement of paddles overcomes this difficulty and enablesme to in- --each paddle until after the liquor has been dischargedtherefrom or'frorn the space between the discs at the respective ends thereof, thereby aid- -ing in the production of a uniform spray.

Therespective end portions-of the shaft 15 extend outwardly through and beyond openings 24 in the sidewalls 11 of the receptacle and they are fitted to rotate in bearings 25 which are secured to the. side ar-ms26 of a frame 2'? which comprises the side arms 26 and a bar 28 conheating the forward ends thereof and formed inprojections 36 formed on the receptacle. central portion of the frame bar 28 has a bracket tegral therewith or secured thereto. The rearward ends of the side arms 26 are pivotally --mounted on the rearward portion of the receptacle 9 by means of a suitable rod or shaft 29 which extends through the arms 26 and through lugs or The 31 secured thereon to which a block 32 is pivoted.

Screwed into this block 32is the lower, threaded *end portion of a shaft 33 which extends upwardly therefromand' through and above an opening in a forwardly projecting lug 34 on' the receptacle 9. The shaft 33 also extends through upper and lower plates 35"and 36 arrangedabove and'below the lug 34, respectively, and connected at their ends by bolts 37. The upper end of the shaft 33 has a hand wheel 38 secured thereon, the hub of which is pressed down upon the upper plate 35 by the action of a helical spring 39 which encircles the shaft 33 between the lower plate 36 and a collar 40 secured to the shaft. This spring 39 is provided to hold the shaft 33 firmly in different positions to which itmay be turned by operating the hand wheel 38. It will now be understood that the shaft 15 may be raised or lowered within the receptacle 9 by turning the hand wheel 38 and thereby causing the lower threaded end portion thereof, working in the block 32 to raise or lower the frame 27 and therewith the shaft 15, in accordance with the direction in which the wheel 38 is turned. One of the bolts 37 extends upwardly from the plate 35 and into the path of a lug 41 which projects downwardly from the wheel 38 and forms a stop which is adapted to engage the projecting end of the bolt and limit the turning of the shaft 33 to slightly lessthan a complete revolution thereof in either direction and thus prevent over adjustment of the shaft when the wheel38 is turned to raise or lower the same. 7 The upper plate 35 is provided with an upstanding arm or indicator 42 which indicates the extent to which the shaft 15 has been adjusted by the relation of the indicator 42 to the lug 41 or to suitable markings on the wheel.

The provision for the vertical adjustment for the shaft 15 enables me to raise or lower'the paddies 18 and 19 of the liquid spreader with relation to the baflle wall 14 and the liquid level and thereby vary the space between the paddles and the Wall and also vary the' height of the paddles with relation to the liquid level for the fine regulation of the spraying action of the'spraying device.

The side walls 11 of the receptacle are provided with inwardly extending parts 43 through which the openings 24 for the shaft 15 extend, and the sleeves 21, at the respective ends of the spreader sections, are located within the openings 24 in spaced relation to the walls thereof. The wall of each opening 24 is provided with a plurality of annular flanges 44 forming a plurality of annular grooves 45 between them, and

each sleeve 21 is provided with a plurality of annular flanges 46, corresponding in number with and surrounded by the grooves 45 of the wall of its opening 24. The interior diameters of the flanges 44 of each opening 24 and the exterior diameters of the flanges 46 of each sleeve 21 progressively decrease in diameter, respectively,

in an inward direction, and each flange 46 of each sleeve 21has an exterior diameter less than the interior diameter of the next adjacent flange 44 outwardly thereof and greater than the inthe flanges 46 it will be discharged therefrom and into the grooves 45 by centrifugal action, and it will then flow by gravity back into the receptacle 9 through drain passages 4'? leading from Lil-l:

the receptacle.

' In order that the level of the etching liquor 23 may be raised or lowered with relation to the paddles 18 for the proper and efficient operation thereof, I'provide an overflow pipe 49 for the liquor, which extends from the interior to the exterior of the receptacle. This pipe 49' extends through and is supported by a round tapered plug 50 which closes an opening in the forward wall 12 of the receptacle and which may be turned to different positions of adjustment therein. The plug 50 may be formed of rubber or other suitable material and the pipe 49 extends therethrough eccentrically thereto so that the pipe may be raised or lowered, to vary the liquid level, by turning the plug. The end portions of the pipe 49 are turned downwardly, as illustrated, and, after the plug 50 has been adjusted, the pipe 49 may be turned therein to adjust the down turned ends thereof into proper position. The outer down turned end of the pipe 49 discharges into the upper end of a hollow tapered valve plug or stem 51 which is fitted to be turned in a valve body 52 connected to the receptacle 9 and having a passage 53 therein in communication with the receptacle and normally closed by the plug 51. The plug51 has an opening 54 in one side thereof which may be turned into registry with the passage 53 for drawing the etching liquor from the receptacle and into a suitable receiver below the plug 51. When the etching liquor is introduced to the receptacle, the level of the liquor. is governed by the position of the pipe 49, and the overflow of the liquor presses from the outer end of the pipe 49 and into and through the hollow plug 51 down into the said receiver beneath the same.

The lower rearward portion of the receptacle contains a plate-like support 55 for the plates to be etched. This support may be formed of stoneware or other suitable material, and its upper portion is provided with a groove 56 for the reception of the lower edge portions of the plates to be etched. The forward edge of the support 55 abuts against a projection 5'7 on the bottom wall 10 of the receptacle and the rearward edge of the support rests against suitably spaced, parallel ribs 58 which project forwardly from the rear wall 13 of the receptacle and form abutments against which the upper edge portions of the plates to be etched may rest when the plates are placed upon the support 55 within the groove 56 thereof and tilted back against the ribs 58.

To retain the plates to be etched in proper position upon the support 55, I provide a retaining member 59 or block 59 which is fitted to slide vert cally in a guideway formed between parallel ribs on the rear wall 13 of the receptacle. This member 59 is adapted to rest upon the upper edge portions of the plates to be etched and it is provided with a down turned lip 60 for engaging and holdingthe plates in place.

In Fig. 4 I have shown a plate 61 to be etched, resting upon the support 55 and having its upper edge tilted back to the ribs 58, and I have shown the member 59 resting upon the plate 61 and retaining it in place. It will be understood that the member 59 may be moved vertically to accommodate a plate to be etched of any size within the capacity of the machine. The ribs 58 extend the full vertical dimension of the interior of the receptacle, or substantially so, to receive the upper edge portions of plates to be etched ofvarying sizes and support them in spaced relat'on to the rear wall 13 and to provide passages between them for the down flow of etching liquor back of the plates.

The flaring spray of etching liquor delivered by the spraying device covers the entire rear wall 13 ofthe receptacle above the support 55, so that all parts of a' plate to be etched of any size within the capacity of the machine will be reached and acted upon by the sprayed etching liquor, and the purpose of providing the passageways between the ribs 58 is to permit the sprayed liquor which is projected toward the wall 13 above the plate to be etched to flow down back of the plate and prevent it from flowing down over the forward surface of the plate and thereby prevent the undercutting which has heretofore occurred where the sprayed liquor above the plate has been directed to the forward surface thereof by the rear wall of the receptacle and thus permitted to flow down over the forward surface of the plate.

The top of the receptacle is normally closed suitable cover plates 62 and 63 which rest upon ledges formed on the walls 11 and 13 a slight distance below the top thereof. Oneor both of these plates may be easily removed to afford access to the interior of the receptacle for the introduction of the etching liquor thereto and for the insertion and removal of the plates to be etched and for other purposes.

The receptacle 9 is provided with a passage 64 leading from the upper portion of the interior thereof to the exterior thereof, and located within this passage is a fan 65 which is carried and actuated by the power shaft of an electric motor 66 for the purpose of drawing a continuous stream of air into the receptacle 9 through the openings 24 and exhausting it through the passage 64 in accordance with'the common practice in etching machines. 1

I claim as my invention:

1. In an etching machine, the combination of a receptacle to contain the etching liquor, a shaft extending horizontally within the receptacle above the liquor level thereof, means for rotatably supporting the shaft, a liquid spreader carried by the shaft and provided with paddles alined for rotation in a common path, one of said paddles extending a greater distance from the axis of the shaft than" another, and a bafile wall extending from saidsde wall above the spreader.

2. In an etching machine, the combination of a receptacle to contain the etching liquor, a transversely extending shaft therein, means for rotat-' ably supporting the shaft, a liquid spreader carried by the shaft and provided with long and short paddles alined for rotation in a common path, the long paddles alternating with the short paddles and extending a greater distance from the axis of the shaft than theshort paddles, and a bafile wall extending from said side wall above the spreader.

In an etching machine, the combination of a receptacle to contain the etching liquor, a shaft extending horizontally within the receptacle above the liquor level thereof, means for rotatably supporting the shaft, a liquid spreader carried by the shaft and provided with paddles alined for rotation in a'oommon path, said paddles extending outwardly from the shaft one a greater distance from the axis thereof than another and said paddles'having forwardly extending free end portions, and a bafiie wall extending from said side wall above the spreader.

4. In an etching machine, the combination of a receptacle to contain the etching liquor, a transversely extending shaft therein, means for rotatably supporting the shaft, a liquid spreader carried by the shaft and provided with long and short paddles alined for rotation in a common path, the long paddles alternating with the short paddles and extending a greater distance from the axis of the shaft than the short paddles and said paddles having forwardly extending free end portions, and a bafiiewall extending from said side wall above the spreader.

5. In an etching machine, the combination of a receptacle to contain the etching liquor, a transversely extending shaft therein, means for rotatably supporting the shaft, a plurality of liquid spreader sections carried by the shaft and each provided with paddles aimed for rotation in a common path, one paddle of each section extending a greater distance from the axis of the shaft than another paddle of the same section, the short paddles of, each section being arranged op posite to the long paddles of the next adjacent section, and a bafile wall extending from said side wall above the spreader.

6. In an etching machine, the combination of a receptacle to contain the etching liquor, a trans versely extending shaft therein, means for rotatably supporting the shaft, a pluralityof liquid spreader sections carried by the shaft and each provided with long and short paddles alined for rotation in a common path, the long paddles of each section alternating with the short paddles of the same section and extending a greater distance from the axis of the shaft than the short paddles, the short paddles of each section being arranged opposite to the long paddles of the next adjacent section, and a bafiie wall extending from said side wall above the spreader.

7. In an etching machine, the combination of a receptacle to contain the etching liquor, a transversely extending shaft therein, means for rotatably supporting the shaft, a plurality of liquid spreader sections carried by the shaft and each provided with paddles alined for rotation in a common path, one paddle of each section extending a greater distance from the axis of the shaft than another paddle of the same section and said paddles having forwardly extending free end portions, the short paddles of each section being arranged opposite to the long paddles of the next adjacent section, and a bafiie wall extending from said side wall above the spreader.

8. In an etching machine, the combination of a receptacle to contain the etching liquor, a transversely extending shaft therein, means for rotatably supporting the shaft, a liquid spreader carried by the shaft and provided with long and short paddles alined for rotation in a common path, the long paddles of each section alternating with the short paddles of the same section and extending a greater distance from the axis of the shaft than the short paddles of the same section and said paddles having forwardly extending free end portions, the short paddles of each section being arranged opposite to the long paddles of the next adjacent section, and a baiile wall extending from said side wall above the spreader.

9. In an etching machine, the combination of a receptacle to contain the. etching liquor, a transversely extending shaft therein, means for rotatably supporting the shaft, a plurality of liquid spreader sections carried by the shaft and each provided with long and short paddles alined for rotation in a common path, the long paddles of each section alternating with the short paddles of the same section and extending a greater distance from the axis of the shaft than the short paddles, and the short paddles of each section being arranged opposite to the long paddles of the next adjacent section, discs carried by the shaft and closing the ends of the spaces between the paddles of the spreader sections, and a baflie wall extending from said side wall above the spreader.

10. In an etching machine, the combination of a receptacle to contain the etching liquor, a transversely extending shaft therein, means for rotatably supporting the shaft, a liquid spreader carried by the shaft and provided with long and short paddles alined for rotation in a common path, the long paddles of each section alternating with the short paddles of the same section and extending a greater distance from the axis of the shaft than the short paddles of the same section and said paddles having forwardly extending free end portions, and the short paddles of each section being arranged opposite to the long paddles of the next adjacent section, discs carried by the shaft and closing the ends of the spaces between the paddles of the spreader sections, and a baiiie wall extending from said side wall above the spreader.

11. In an etching machine, the combination of a receptacle to contain the etching liquor, a frame movably mounted on the receptacle and provided with spaced bearings, a shaft rotatably carried by said bearings and extending transversely through the receptacle, a liquid spreader carried by the shaft between the bearings, and means operable to raise and lower the frame.

12. In an etching machine, the combination of a receptacle to contain the etching liquor,'a frame embracing said receptacle and comprising laterally spaced arms and a bar connecting the forward. ends thereof, the rearward end portions of said arms being pivoted to the receptacle, a shaft rotatably carried by said arms and extending transversely through the receptacle, a liquid spreader carried by the shaft, and means operable to raise and lower the frame.

13. In an etching machine, the combination of a receptacle to contain the etching liquor, a frame movably mounted on the receptacle, a shaft rotatably carried by the frame and extending transversely through the receptacle, a liquid spreader carried by the shaft, a hand operated shaft rotatably mounted on the receptacle,and

means operated by the last named shaft for raise ing and lowering the frame.

14. In an etching machine, the combination of a receptacle to contain the etching liquor, a frame embracing said receptacle and comprising laterally spaced arms and a bar connecting the forward ends thereof, the rearwardend portions of said arms being pivoted to the receptacle, a shaft rotatably carried by said arms and extending transversely through the receptacle, a liquid spreader carried by the shaft, a hand up: erated shaft rotatably mounted on the receptacle, and means operated by the last named shaft for raising and lowering the frame.

15. In an etching machine, the combination of a receptacle to contain the etching liquor, a frame embracing said receptacle and comprising laterally spaced arms and a bar connecting the forward ends thereof, the rearward end portions of said arms being pivoted to the receptacle, a shaft rotatably carried by said arms and extending transversely through the receptacle, a liquid spreader carried by the shaft, a block ivotally connected to the frame and provided with a threaded opening, and a hand operated shaft rotatably mounted on the receptacle and provided with a screw in engagement with the thread of the opening in the block for raising and lowering the frame when the hand operated shaft is turned.

16. In an etching machine, the combination of a receptacle to contain the etching liquor, said receptacle having an opening in a side wall thereof, a shaft extending transversely within the receptacle and through said opening and carrying a liquid spreader, the wall of said opening having outer and inner annular flanges spaced longitudinally of the shaft and forming an annular groove between them, said groove having a drain passage leading from the lower portion thereof to the interior of the receptacle, a sleeve carried by the shaft and having an annular flange surrounded by said groove and having an exterior diameter less than the interior diameter of said outer flange and greater than the interior diameter of said inner flange, and means for rotatably supporting the shaft.

17. In an etching machine, the combination of a receptacle to contain the etching liquor, said receptacle having an opening in a side wall thereof, a shaft extending transversely within the receptacle and through said opening and carrying a liquid spreader, the wall of said opening having a plurality of annular flanges spaced longitudinally of the shaft and forming a plurality of annular grooves between them, said grooves having drain passages leading from the lower portions thereof to the interior of the receptacle, a sleeve carried by the shaft and having a plurality of annular flanges. corresponding in number with and surrounded by said grooves, the interior diameters of the flanges of said opening and the exterior diameters of the flanges of the sleeve progressively decreasing in diameter, respectively, in the same direction longitudinally of the shaft, and means for rotatably supporting the shaft. I

18. In an etching machine, the combination of a receptacle to contain the etching liquor, means for spraying liquid within the receptacle toward a wall thereof, and Vertically extending means for supporting a plate to be etched Within the receptacle with its upper end adjacent to but spaced from said wall for the downward passage of liquid laterally of the last named means between the Wall and the upper end of the plate.

19. In an etching machine, the combination of a receptacle to contain the etching liquor, means for spraying liquid within the receptacle toward a wall thereof, and a support within the tank for receiving the bottom of a plate to be etched, said wall having vertically extending parts forwardly thereof to support said plate with its upper end spaced from the wall when the plate is tilted on said support, and said parts providing passages between them for the downward passage of liquid between the wall and the plate.

20. In an etching machine, the combination of a receptacle to contain the etching liquor, means for spraying liquid within the receptacle toward a wall thereof, and a support within the tank for receiving the bottom of a plate to be etched, said wall having ribs projecting therefrom and extending in a direction from the top to the bottom of the receptacle to support the upper portions of plates to be etched when tilted on said support, and said ribs providing passages between them for the downward passage of liquid between the wall and the plate.

21. In an etching machine, the combination of a receptacle to contain the etching liquor, a wall of the receptacle having a round opening extending therethrough above the bottom of the receptacle, a plug closing said opening, and an overflow pipe leading from the interior to the exterior of the receptacle and supported by and extending through said plug eccentrically thereto.

WILLIAM GUENST. 

